HPD and liver cancer: HPD is known as a key enzyme in the tyrosine catabolism pathway, which is involved in metabolizing 4‐HPPA to HGA, and its deficiency usually leads to the hereditary type III tyrosinemia.[28] Emerging evidence has revealed that the dysregulation of HPD expression also as a driver in breast cancer, lung cancer, and liver cancer progression.[8, 29, 30] Although the non‐metabolic functions of HPD in cancer progression have been explored, it remains poorly understood that more non‐metabolic functions of HPD are related to cancer and disease.